Incandescent lamp and similar device



March, 1931.- R. @.PHELPS I INCANDE'SCENT LAMP AND'SIMILAR DEVICE Filed April 29, 1927 JNSZENTDR.: EDSDDE GI HELPE :5y

.l Hz-s' ra-aansla- Patented Mar. 3, 1931 y UNITED STATES PivrlazNT OFFICE BOSCOE PHELPS, F CLEVELAND, OHIOASSIGNOB T0 GENERAL ELECTRIC COMPANY, A CORPORATION 0F NEW YORK Application led April 29,

My invention relates to electric incandescent lamps and similar devices comprising a bulb, a filament and a base, and more particularly to improvements in methods of manufacture thereof having as their object the production of devices having the said parts in more uniformly accurate relation and alignment.

The features of my invention and the advantages thereof will appear from the following description of a species thereof and from the claims. In general my invention consists in the production of a bulb having a neck portion which has a portion thereof formed definitely so that when a base is subsequently seated over said portion it will be axially aligned with the bulb and spaced a definite distance from the filament. Moreover, according to my invention, the sealing 2U of the mount in said bulb is so accomplished that the seating portion of said neck is substantially retained.

In the drawing Fig. 1 is an elevation of a bulb formed according to my invention; Fig.

2;, 2 is a similar view showing the completed lamp; Fig. 3 is a similar view of an old form of bulb; Figs. 4 and 5 are views showing cases of faulty alignment arising from the use of said old form; and Fig. 6 is an elevation of 3U a lamp embodying my invention equipped with a bayonet type base.

The bulb shown in Fig. 1 is blown with a bowl portion 10 and a neck portion 11. At their junction there, is a comparatively sharp 3.3 contraction resulting in a shoulder 12 and below said shoulder the constricted portion A is definitely dimensioned and shaped for a short distance to conform to the kend' portion of a base shell.

1o Uien the filament mount which ordinarily comprises a flared stem tube is sealed into the bulb, the lower portion of the bulb neck is melted off. However, according to my invention, the sealing-in is accomplished Without 4: removing all of the portion (A). As shown INCANDESCENT LAMP AND SIMILAR DEVICE 192?. serial' Nu. 187,626.

in Fig. 2, after the sealing-in operation which causes the bulb neck to be contracted at 13 to engage the seal with the are 14 of the stem, there still remains the portion 15 of the original portion (A). The result is that when the base 16 is placed in'fposition to be united with the bulb, the end portion 17 of the base engages the shoulder 12 and the accurately dimensioned portion 15 thus valigning the base and positioning it a -defnitedistance from the filament which has been accurately sealed in the bulb. In the form shown in Fig.

6 the base is so positioned that the ins 18 are accurately positioned -a definite istance from the filament of the lamp on account of the engagement of the end of the base with the shoulder. The base of the filament is indicated at 00.

In Fig. 3 is shown the old form of bulb. The absence of a shoulder such as 12 of Fig. 65 1 and of the portion A immediately therebelow renders accurate sealing-in difficult. The result is that the sealing-in operation causes an irregular shoulder to be formed on the bulb neck, as shown at 19-20 in Fig. 4, and 70 21-22 in Fig. 5. When the bases are slipped, over the end of such bulbs they are not properly aligned with the bulb or filament and not only present an unattractive appearance but render the definite positioning of a fila- Vthereloelow and conforming totheinterior end portion ofthe base, sealing-infthe filarnent mount while preserving a substantial part of said base seating portion, and then positioning the base with the end portion thereof engaging said base seating portion and uniting the base to said bulb.

2. An incandescent lamp comprising a fila-- ment, a bulb comprising a neck having a shoulder and a portion extending a substantial distance therebelow and accurately disposed axially with reference to said filament and a base comprising an end portion having an inner surface conforming to the surface of said neck portion and seated thereon.

In witness whereof, I have hereunto set my hand this 27th da of A ril, 1927.

08() E G. PHELPS. 

